A breakdown of the most efficient cargo configurations for leased freighter income
Freighter efficiency, hullform to hullform, is difficult to generalize. Different classes of freighters (i.e. FT2, FT3, FT4) have differing hull costs and engine requirements. However, general trends can be noted that inform the decision-making process once the basic hull type is known.
Freighters discussed here do not have their designs shown in detail, but systems correspond to the rules in L4.04 for CFN freighter design: the minimum-cost commercial engine set required to achieve the target speed (4 unless otherwise noted), no more life support capacity than is required for the design, and otherwise only H or Qv systems. One deviation: all designs have the maximum number of Hb cargo bays present, as this is expected to become a CFN requirement in the next rules revision. All freighters are on alpha-generation hulls unless noted otherwise. Only FT2 - FT5 freighter classes have been considered.
Return on Investment
The basic measure of effectiveness for this article is Return on Investment, or ROI. What percentage of the cost of the freighter (or portion thereof) is returned as a profit each month? This is a useful basic bang-for-the-buck measure and can be loosely compared to other returns available to a Starfire empire: 3.3% from IU purchases or 2% in treasury interest.
Absent other considerations (such as the cost of a freighter's engines), H systems provide a larger ROI in isolation than do Qv (1 MCr income from a 1 MCr system against 1.6 / 5.5). As such, H-only freighters form the starting point for this analysis. As a rough starting point, H-only freighters earn about a 5% ROI.
Refitting H to Qv
One substantial practical advantage of H over Qv is that the former does not require life support, and so large freighters can earn a profit without paying for life support capacity for the whole hull. However, within the constraints of mandatory life support capacity, Qv will produce more raw income than H. What is the ROI of an H-to-Qv refit? We determine this via the following formula, used in this general form throughout the article: ( Δincome - Δmaint ) / Δcost . Δincome is the difference in income when replacing an H with a Qv (0.6 MCr), Δcost is the difference in the system cost of that replacement (4.5 MCr), and Δmaint is the difference in maintenance — Δcost times the FT maintenance rate of 7.5% (0.3375 MCr). The ROI for an H-to-Qv refit, then, is 5.8%. An H-only freighter with an ROI less than 5.8% benefits from swapping H to Qv within the limits of its available life support; an H-only freighter with an ROI greather than 5.8% benefits by remaining H-only.
This benchmark changes at higher speeds — Δincome increases by speed/4 while Δcost remains fixed. At speed 5, the H-to-Qv ROI is 9.2%; at speed 6, it is 12.5%. Fast freighters are better equipped to recover the additional costs of mounting Qv systems. H-only fast freighters are frequently not economically competitive.
Adding Life Support Capacity
The above ROI calculations stipulated "within the constraints of existing life support"; what about adding more life support for Qv? There are two ways this can be done: upgrading an existing Q system or adding an additional Q system.
This scenario posits replacing a Qa system with a Qb, Qe, or other higher-generation life support system. It preserves the number of HS that the freighter can devote to cargo systems. The ROI calculation is similar to the initial Refit equation, but must prorate the cost of the more expensive Q system across the number of additional Qv it allows. Δcost now includes a term for ( Qxcost - Qacost ) / ( QxHS - QaHS ). For an initial Qa-to-Qb refit, this term is 1: Qb is 5 MCr more expensive and supplies life support to 5 additional HS, so each Qv refitted must also account for 1 MCr of additional life support costs.
The presence of this additional cost is an immediate tip-off that this sort of refit is less profitable than one that uses only existing life support. For upgrades to early Q systems (Qb, Qe, and Qi), the ROI is 3.4%. From there, life support is progressively less cost-effective, and the ROI settles around 3%. As basic H-only freighter designs have an ROI around 5%, this refit path is never profitable for a speed-4 freighter.
Adding More Q
The final case is simple to explain (rather than paying for a more expensive Q system, mount an additional Qa system), but has by far the most complex calculation — in addition to prorating the cost of the extra Q, Δincome must account for the lost income of the HS that now mounts the extra Q. This ROI works out to only 2.8%, even worse than the Q upgrade option (which, as noted, is never profitable for a speed-4 freighter). The ROI can be improved slightly: because upgrading Qa to Qb, Qe, or Qi has an ROI above 2.8%, the two approaches can be combined. Qi ends up being the optimal spot, with multiple installations giving an ROI of 3.0% — still the lowest of the refit options.
Calculations for Q adjustment at higher speeds are done with the same adaptation used in the H-to-Qv refit.
At speed 5, a Qa-to-Qi upgrade has a 6.1% ROI and an extra installation of Qi has a 5.8% ROI. The Q upgrade ROI is roughly on par with the baseline ROI of a speed 5 freighter; while such an upgrade is not a money-maker, it is not a substantial money loser, either. Multiple Q installations remain a money-losing proposition.
At speed 6, a Qa-to-Qi upgrade has an 8.9% ROI and an extra installation of Qi has an 8.4% ROI. Both numbers are above the baseline ROI of a speed 6 freighter; these freighters should typically be optimized for Qv capacity.
In summary, freighters designed with profit as the primary objective should mount as little life support as possible. Within the constraints of that life support, replacing H with Qv is generally profitable so long as the H-only freighter's ROI is below a particular threshold (5.8% at speed 4, and progressively higher at higher speeds).
Basic Freighter Optimization
The particulars of freighter ROI vary from hull class to hull class due to the vagaries of engine requirements and residual life support capacity. Rather than cross-class analysis, brute force processing of each type is necessary to find the most profitable configurations. As brute force processing is dull, this section will note only the results.
The most economically effective basic freighter is an H/Qv-mix FT4 (14 H, 6 Qv) with an ROI of 5.3%. Close behind are an H-only FT4 (20 H) and an H/Qv-mix FT3 (8 Qv, 6 H) at 5.1% each. The most effective Qv-only basic freighter is a Qv-only FT2 (10 Qv) at 4.9%; this freighter, rather than a larger hull form, is the most efficient of its type because it does not require a life support upgrade; the existing Qa is enough to support all of the HS that the unit can dedicate to cargo.
An FT5 freighter is unattractive due to the requirement for an additional Hb; the H-Only and H/Qv-mix designs each return only 4.9%.
Advanced Hull Forms
Many games use the optional rule for generational hulls. Increasing the generation of a freighter hull substantially increases its ROI, even with the increased cost of higher-generation engines, because all of the new HS can be devoted to cargo systems (contrast with increasing the hull class, which necessitates more space devoted to engines). Basic-hulled freighters have an ROI of about 6%, making H-only designs the most profitable, although H/Qv-mix designs are comparable. ROI increases further with each later hull generation, and H-only freighters clearly surpass the ROI of H-to-Qv refits at Enhanced and later hull generations. The most profitable freighter class is not constant from generation to generation.
For Basic hulls, FT3b designs (either H-only or H/Qv-mix) have the best ROI at 5.9%. FT5b trails at 5.6%, followed by FT4b plummeting to 5.4%, lagging due to the second Hb.
For Enhanced hulls, an FT3e H-only hull has the highest ROI at 6.8%. An FT2e has a 6.6% ROI, followed by FT4e and FT5e at 6.1%. All H/Qv-mix versions have an ROI 0.2% less than their H-only counterparts.
Fast freighters see a dramatically higher ROI from Qv; H-only fast freighter designs are never preferable. At speed 6, Q systems should be upgraded and/or added to permit Qv-only designs.
At speed 5, an FT3 H/Qv-mix (7 Qv, 6 H) has the highest ROI at 6.6%. At speed 6, an FT3 Qv-only design using Qb (11 Qv, 1 H) has the highest ROI at 7.7%. FT3 fast freighters have significantly higher ROIs than other freighter classes due to a quirk in engine requirements for the FT3 — while all other freighter classes require a 50% increase in engine space to go from speed 4 to speed 6, FT3 freighters require only a 33% increase in engine space. Thus, they devote proportionally more HS to cargo systems.
If generational hulls are available, FT3b freighters are similarly superior to their counterparts. At speed 5, an FT3b H/Qv-mix design (7 Qv, 10 H) has the highest ROI at 7.7%. At speed 6, an FT3b H/Qv-mix design (6 Qv, 10 H) has the highest ROI at 9.2%. As ROIs continue to rise with later-generation hulls, H/Qv-mix designs will likely eventually yield to H-only designs again.
All analysis on fast freighters assumes that lease income is multiplied by speed/4. Fast freighter analysis has only considered speeds 5 and 6. Fast freighter analysis has only considered FT2 - FT5.